PLEASE HELP!!!!
7. According to Mohs Hardness scale, which of these groups of minerals can scratch fluorite? А. B. talc, calcite, and apatite calcite, quartz, and topaz apatite, orthoclase, and corundum diamond, gypsum, and quartz C.
Answer:
B
IS THE CORRECT ANSWER
Elements in a ___ on the Period Table of Elements have similar chemical characteristics and properties.
In what way is Model A better than Model B? Model A shows the types of elements in the compound, but Model B does not. Model A shows the total number of atoms in the molecule, but Model B does not. Model A shows the three-dimensional shape of the molecule, but Model B does not. Model A shows the number of atoms of each element in the molecule, but Model B does no
Answer:the answer is c babes
Explanation:
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Have a nice day
Or whatever day u want LMA0 it’s not up to me. Ight peace loves
Model A is better than Model B as Model A shows the three-dimensional shape of the molecule, but Model B does not. The correct option is c.
What are molecules?The smallest particle of a substance possesses all of its physical and chemical properties. One or more atoms make up a molecule.
Knowing the molecular weights of the molecules allows us to calculate their sizes. The molecular weight of a molecule is the sum of the atomic weights of the atoms in the molecule.
The relative atomic mass of particles determines their size. Particles with a higher relative atomic mass weigh more than particles with a lower relative atomic mass. Larger atoms have heavier iotas and a larger relative atomic mass.
Therefore, the correct option is c, Model A shows the three-dimensional shape of the molecule, but Model B does not.
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how does an electron emit light?
Answer:
by moving between defined energy levels
TRUE or FALSE: The rock closest to the ridge is newer and younger than the older rock
further away from the ridge.
Answer:true
Explanation:
How many moles are there in 32.4 grams of Na
According to the mole concept, there are 1.4087 moles in 32.4 grams of sodium.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles in this case is obtained by dividing mass by molar mass that is, 32.4/23=1.4087 moles.
Thus, there are 1.4087 moles in 32.4 g of sodium.
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How many grams of CaCI2 (molar mass = 111 g/mol) are needed to prepare 100.mL of 0.100 M CI-(aq) ions?
a.) 0.555 g
b.) 1.11 g
c.) 2.22 g
d.) 5.55 g
I will mark as brainliest if you give the correct answer (brief explanation only, no worries)
Answer:
a
Explanation:
Because that is the answer
Find the percent of water in Zn3(PO4)2 x 7H2O
Answer:
24.66%
Explanation:
To find the percent of water (H2O) in the following compound: Zn3(PO4)2. 7H2O
The atomic mass of the elements are as follows:
Zn = 65g/mol
P = 31g/mol
O = 16g/mol
H = 1g/mol
Hence, molar mass of the compound is as follows:
65(3) + {31 + 16(4)} 2 + 7{1(2) + 16}
195 + 95(2) + 7(18)
195 + 190 + 126
511g/mol
Molar mass of 7H2O
= 7(18)
= 126g/mol
Hence, the percent of H2O in the compound is:
Molar Mass of 7H2O/molar mass of compound × 100
= 126/511 × 100
= 0.2466 × 100
= 24.66%
2. Why is soil considered limited?
Answer: he natural area of productive soils is limited – it is under increasing pressure of intensification and competing uses for cropping, forestry, pasture / rangeland and urbanization, and to satisfy demands of the growing population for food and energy production and raw materials extraction
Agree or disagree
one rotation of the earth occurs everyday or 24 hours
Answer:
Agree
Explanation:
The rotation of earth happens about once every 24 hours.
Solid carbon dioxide (CO2), also known as dry
ice, changes into a gas at room temperature. An
image of this change can be seen below.
Is this an example of a physical change? Why
or why not?
Answer:
yes
Explanation:
yes because the ice changes forms physically and can be changed back. not 100% sure tho
Answer:
shiii ion even know like i cant even tell u tha
Explanation:
bro 2 of my bruddas got locked up 2 days ago one of em got shot before the cops took him
hhhhhhhhhheeelp !!! give 20 pintos
Answer:
you can run out of money the supplier could run out or they could stop making the renewable.
Explanation:
What happens to alpha particles as they get closer to the gold nucleus?
Answer:
Initially the alpha particle has only kinetic energy EK. As it approaches the gold nucleus it suffers repulsion by the 79 protons within that nucleus. Its kinetic energy changes into electric potential energy EP.
All of these are examples of compounds except
Answer:
Add a picture please! or give answer choices
Explanation:
Answer:
theres no examples
Explanation:
i can answer if you add examples
two negative charges are placed near each other. what happens between the charges
Answer:
repulsion
Explanation:
Answer:
Explanation:
In contrast to the attractive force between two objects with opposite charges, two objects that are of like charge will repel each other. ... Similarly, a negatively charged object will exert a repulsive force upon a second negatively charged object. Objects with like charge repel each other.
12) Which model of the atom is thought to be true?
a. Protons, electrons, and neutrons are evenly distributed throughout the volume of
the atom.
b. The nucleus is made of protons, electrons, and neutrons.
c. Electrons are distributed around the nucleus and occupy almost all the volume of
the atom.
d. The nucleus is made of electrons and protons.
Answer:
B
Explanation:
The neucles is surrounded by electrons. Electrons occupy most of the volume of the atom.
Atomic Model:
Atoms are the smallest unit of elements, which form bonds with others. In an atom, electrons revolve around the nucleus.
The nucleus is composed of positively charged protons and neutrons. The nucleus occupies a very small part of the atom.
Electrons are negatively charged particles, they are found around the nucleus and occupy most of the part of the atom.
Therefore, The neucles is surrounded by electrons. Electrons occupy most of the volume of the atom.
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Help plz 15 pointsss
Can someone define these for me
Answer:
These are all in order....
Explanation:
- closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system
- a solute is a substance dissolved in another substance, known as a solvent
- A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid
- a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent)
- a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy
- a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
- Half-life is the time required for a quantity to reduce to half of its initial value
- the determination of the age or date of organic matter from the relative proportions of the carbon isotopes carbon-12 and carbon-14 that it contains. The ratio between them changes as radioactive carbon-14 decays and is not replaced by exchange with the atmosphere.
- any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed
PLEASE HELP ASAP I NEED THIS THANK YOU SOO MUCH
which of the two chemical equations follow the Law of Conservation of Mass
Equation A: Zn +2HCl —> ZnCl2+ 2H2
Equation B: Zn +2HCl —> ZnCl2 + H2
Equation A: Zn +2HCl —> ZnCl2+ 2H2
What goes in photosynthesis and what comes out of photosynthesis?
Answer:
Carbon dioxide goes in and oxogen comes out
P.S. Sunlight needed for this process to work
Explanation:
How much energy is required to vaporize 14.27 grams of water at its
boiling point? *
Energy required to vaporize : 32.3 kJ
Further explanationThe heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
Mass of water = 14.27 g
Latent heat of vaporization ( boiling point of 100 ºC) : 2260 J/g
Energy required :
[tex]\tt Q=m.Lv\\\\Q=14.27\times 2260\\\\Q=32250.2~J\approx 32.3~kJ[/tex]
THIRTY POINTS I NEED HELP HURRY What is the volume of the cone?
Answer:
V=πr2h 3
Explanation: I would give more but need more i information
Answer:there u go
Explanation:The volume V of a cone with radius r is one-third the area of the base B times the height h . Note : The formula for the volume of an oblique cone is the same as that of a right one. ... If the heights of a cone and a cylinder are equal, then the volume of the cylinder is three times as much as the volume of a cone
Fill in the blanks. A person would weight more on Neptune than on planet blank
because
blank
A person would weigh more on Neptune than on planet earth because the gravitational field strength is stronger on Neptune.
A person would weight more on Neptune than on planet earth because the gravitational force in neptune is more.
What is gravitational force?Gravitational forces is a kind of attraction force which is present between two objects of masses.
Gravitational force on the neptune planet is more as compared to the gravitational force on the earth. So the mass of any object present in the neptune is more than the earth.
Hence a person would weight more on Neptune than on planet earth because gravitatinal force in neptune is more.
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You are making lemonade and the calls for 6 cups Lemon juice (L), 3 Cups of sugar (S) and 5 cups of water (W) to make 12 Cups of Lemonade (LA): your formula is:
6 L + 3 S + 5 W = 12 LA
You are given 9 cups of lemon juice (L), 8 cups of sugar (S) and unlimited water (W).
How many cups of lemonade can you make?
1. 9
2. 12
3. 18
4. 32
Answer:
18 Cups
Submitted the assignment
Explanation:
If 0.42 mole of helium occupies 9.9 L, how
many moles must be added to inflate the
balloon to 17.0 L?
0.301 moles
Further explanationAvogadro's hypothesis:
In the same T,P and V, the gas contains the same number of molecules
So the ratio of gas volume will be equal to the ratio of gas moles
Given
n₁=initial mol of Helium : 0.42
V₁=initial volume : 9.9 L
V₂=final volume : 17 L
Required
number of moles added
Analysis
Use formula :
[tex]\tt \dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}[/tex]
Solution
[tex]\tt n_2=\dfrac{n_1\times V_2}{V_1}\\\\n_2=\dfrac{0.42\times 17}{9.9}\\\\n_2=0.721~moles[/tex]
moles added :
0.721 - 0.42 =0.301 moles
Paraphrase
0.301 moles must be added to inflate the balloon to 17.0 L
Determine the number of moles in 5.25x1024 formula units if lead (IV) oxide.
Answer:
8.72 mol PbO₂
General Formulas and Concepts:
Chemistry - Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
5.25 × 10²⁴ formula units PbO₂
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[tex]5.25 \cdot 10^{24} \ formula \ units \ PbO_2(\frac{1 \ mol \ PbO_2}{6.022 \cdot 10^{23} \ formula \ units \ PbO_2} )[/tex] = 8.71803 mol PbO₂
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
8.71803 mol PbO₂ ≈ 8.72 mol PbO₂
True or False: Sulfur by itself isn't too bad, it's when it reacts with other elements that it can become dangerous
Answer:sulfer by itself is not pleasant and it can be dangerous by itself but in large amounts.
Explanation:
Answer:
True.
Explanation:
Also did you know that it is combined with chlorine that it becomes salt? Cool right? Two deadly things combining to become a condiment
____ Ca3(PO4)2(s) + ____ H3PO4(l) → ____ Ca(H2PO4)2(s) When the equation above is balanced and all coefficients are reduced to lowest whole-number terms, what is the coefficient for H3PO4(l)
The equation can be balanced using suitable integers multiplied either side and can be written as follows:
[tex]\rm Ca_{3} (PO_{4})_{2} + 4 H_{3}PO_{4} \rightarrow 3 Ca (H_{2}PO_{4})_{2}[/tex]
Thus the coefficient of H₃PO₄ is 4.
What is balanced reaction?A balanced chemical equation of a reaction represents all the reactants and products in the perfect stoichiometric ratios where, the number of each element have to be equal in both sides.
The given reaction is an example of combination reaction. The equation can be balanced by equating the number of calcium in the product side by multiplying with 3 and then making the phosphate group also balanced by multiplying by 4 with H₃PO₄.
Thus, the balanced chemical equation written above contains 3 calcium on both side and equal number of phosphate group (6) as well as hydrogens on both side where, the coefficient of H₃PO₄ is 4
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can you pls help me with this question
Answer:
probably c
Explanation:
Answer: I feel like the correct answer is choice C but I really don’t know how to explain it..
What is the hybridization of the carbon in the HCN molecule?